Super Smash Brothers Ultimate - Is that canon?

Or the part about how Ridley built Mecha Ridley himself, since that info only comes from an obscure interview with Yoshio Sakamoto on the Japanese website, meaning it's something a casual Metroid fan probably wouldn't know. But I think you're probably right: it's most likely just Pit jokingly questioning Viridi's (somewhat hypocritical) claim that Ridley is "officially […] a narcissist."

Really, there are so many parts of Viridi's statement that Pit could be doubting. I don't know why so many people jump to the conclusion that it's questioning whether or not Zero Mission itself is canon just because it's a remake.